COVID-19 symptoms and obesity in Korean airline crew

doi:10.21203/rs.3.rs-4708551/v1

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Research Article

COVID-19 symptoms and obesity in Korean airline crew

https://doi.org/10.21203/rs.3.rs-4708551/v1

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Background

We aimed to investigate the differences in coronavirus disease 2019 (COVID-19) symptoms according to weight among flight and cabin attendants in Korea.

Methods

This study was designed as a cross-sectional survey, comprising 180 airline crew members.

Results

Out of 180 participants, 22 participants had no symptoms at the onset. Among the 158 participants who experienced symptoms, the most common ones were fatigue (79.7%), cough (63.9%), and myalgia (63.3%). Participants who did not currently smoke and drank less than once a month reported more symptoms of COVID-19. The number of COVID-19 symptoms was significantly higher in participants with normal weight compared to those who were overweight/obese (p = .004). The time taken to return to flight duties after completing COVID-19 treatment was significantly longer for participants with normal weight compared to those who were overweight/obese (p = .041).

Conclusion

Airlines should make efforts to manage fatigue in airline crew members infected with COVID-19. Additionally, smoking and weight have an impact on the severity of COVID-19 in young people; therefore, continuous management is necessary, even if the number of reported symptoms is small.

cockpit crew

cabin crew

fatigue

obesity

smoking

Since the first report of coronavirus disease 2019 (COVID-19), the global number of coronavirus cases has reached 777 million, with 7 million deaths reported by March 2024 by the World Health Organization. Various symptoms of COVID-19 have been identified, including asymptomatic symptoms, fever, fatigue, cough, difficulty breathing, diarrhea, loss of smell, and headache.¹ Symptoms are subjective; therefore, they can vary depending on an individual's perception of their condition. Older individuals with chronic diseases tend to experience more symptoms, and psychological factors also play a role in symptom complaints ². Moreover, psychiatric symptoms such as anxiety and depression have been reported.^{3, 4} In cases of post-COVID-19 syndrome, where symptoms persist for > 12 weeks, sleep quality and overall quality of life are also affected.⁵

The severity of COVID-19 is related to the type and number of symptoms reported after infection. Participants experiencing dyspnea have a high severity of the disease ⁶. When individuals report a high number of symptoms (5 or more), they have a high rate of admission to the intensive care unit ^{1, 7, 8}. Health promotion behavior is another factor that affects the severity of COVID-19 symptoms. Smoking, for example, has been found to increase the severity of respiratory diseases. Both active smoking and a history of smoking have been associated with increased severity of COVID-19 ⁹, and smokers tend to report a higher number of symptoms after being infected compared to nonsmokers ¹⁰. On the other hand, engaging in high levels of physical activity and maintaining healthy eating habits have been linked to reduced symptom severity ^{11, 12}. Obesity has also been identified as a factor affecting COVID-19 severity, particularly among individuals under the age of 65 years. Obese or overweight individuals tend to experience more respiratory symptoms compared to those with normal weight, even when infected with a similar coronavirus ¹³. Furthermore, being underweight is associated with greater severity, possibly due to malnutrition and muscle deterioration ^{14, 15}.

Airline crew members have a lower obesity rate and a higher rate of being underweight compared to the general population. However, during the COVID-19 pandemic, they may have difficulty maintaining proper eating habits due to restrictions on activities to prevent infection and the need to stay in hotels as per each country's regulations while abroad. This could potentially lead to weight changes due to increased food intake frequency. Cabin crew members who have face-to-face contact with passengers may also experience delays in returning to work if they continue to experience symptoms after COVID-19 infection. Therefore, it is important to identify and manage factors that impact COVID-19 symptoms. Weight, in particular, is a cost-effective factor requiring management, emphasizing the importance of evaluating its impact. Infection of airline crew members with COVID-19 is a crucial factor to consider, as it not only affects individual health but also flight safety. However, few studies specifically examined factors influencing symptoms in airline crew members after COVID-19 infection. Therefore, we aimed to explore the impact of weight on COVID-19 symptoms in this population.

Study design

A cross-sectional study design was used to evaluate the factors affecting COVID-19 symptoms and identify differences in COVID-19 symptoms among airline crew members in Korea based on weight.

Participants

Study participants were recruited from airlines in Korea using a convenience sampling technique. The selection criteria for participants were cockpit or cabin attendants who: (1) were currently working at airlines in Korea; (2) had more than one month's experience as a crew member; (3) had tested positive for SARS-CoV-2 at least once or more since 2020 at a public health center or hospital; (4) understood the purpose of the study and voluntarily agreed to participate. For the comparison between normal weight and overweight/obese groups, the sample size was calculated using the G*Power 3.1.9.2 program. The minimum number of participants needed for a statistical power of 0.90 at a significance level of 0.05 and an effect size of 0.5 was 172. Considering an expected dropout rate, a total of 180 participants were recruited. Among the 180 participants, 17 participants were infected with COVID-19 twice from 2020 to the present, and all other participants reported being infected once.

Measurements

1) General questionnaire

The questionnaire for general characteristics included 10 items related to age, sex, smoking, drinking in the past year, regular exercise, height and weight for calculating body mass index (BMI, kg/m²), baseline comorbidity, job, and work experience. Smoking status was determined based on a positive response to the question: "Do you currently smoke?" Drinking was assessed by the question: "Have you consumed alcohol in the past year?" with two response options (less than once a month or more than twice a month). Regular exercise was assessed by the question: "Do you exercise regularly for 30 min or more, three or more times a week?" (yes or no). Obesity was assessed based on BMI using the criteria for the Asia-Pacific region of the World Health Organization.¹⁶ Participants were divided into two groups: normal BMI < 23 kg/m² and overweight/obese BMI ≥ 23 kg/m². Baseline comorbidity was assessed with the question: "Have you been diagnosed with any underlying disease by a doctor?" (yes or no) and "If yes, please provide a detailed description of the name of the disease."

COVID-19-related characteristics were developed based on a previous study¹⁷ and included five items pertaining to the number of COVID-19 symptoms, duration, return to flight duties after treatment or quarantine, and difficulties in daily activities. The number of COVID-19 symptoms, as determined by previous studies^{17, 18}, was assessed by asking participants if they experienced any of the following symptoms at the onset of illness: (1) breathlessness, (2) cough (3) chest pain or discomfort, (4) sleep disturbance, (5) symptoms of anxiety or depression, (6) fatigue, (7) loss of taste, (8) loss of smell (9) myalgia, (10) fever, (11) none, and (12) others (if selected, they were requested to describe the symptom in detail). Participants were allowed to select multiple responses, and this instruction was clearly indicated next to the question to ensure participants were aware.

Symptoms were categorized into eight groups based on a previous study¹⁷: respiratory, cardiovascular, gastrointestinal, psychological, musculoskeletal, neurological, generalized, and ear, nose, and throat symptoms. Furthermore, any duplicated symptoms or those described as "other" were counted and included in the total number of COVID-19 symptoms. The duration of symptoms since the onset of acute COVID-19 infection was assessed by asking participants, "How long did your COVID-19 symptoms last?" The answer options for this question were (1) < 4 weeks and (2) > 4 weeks, to differentiate between acute COVID-19 infection and ongoing symptomatic COVID-19¹⁷. Return to flight duties was assessed by asking participants, "When did you return to flight duties after completing treatment or quarantine for COVID-19?" with two response options: (1) after < 1 week and (2) after > 1 week. Difficulties in daily activities were based on a positive response to the question, "Did you experience any difficulties in daily activities due to post-COVID-19 symptoms?"

Data collection procedures

Data were collected from February to September 2023 through a self-reported online survey. The structured questionnaire was uploaded on an online bulletin board accessible to employees of two airlines in Korea. The first page of the survey contained information about the study's background, purpose, data collection method, contact details for researchers, an explanation of the study's consent process, and a button labeled "I agree". Clicking this button indicated the participant's agreement to participate in the survey.

It took approximately 10–15 min for each participant to complete the questionnaire, and a gift worth 5,000 won was given to those who responded to and completed the survey. Out of the 180 questionnaires obtained from participants who voluntarily clicked the consent button for the study, all questionnaires were complete with no missing data. Finally, 180 valid questionnaires were used for data analysis. All data were treated as confidential.

Ethical considerations

This study was conducted after obtaining approval from the institutional review board (DGU IRB 20230016) of the authors' university. The study's purpose, procedures, and rules were explained to all participants through an online survey. The voluntary nature and confidentiality of the study were emphasized, and participants' personal information was kept confidential. Informed consent was obtained from all subjects.

Data analysis

The data were analyzed using SPSS/WIN 25.0 (IBM Corp, Armonk, NY, USA). Frequencies and percentages were used to analyze the general and COVID-19-related characteristics. Means and standard deviations were used to analyze age, work experience, and the number of COVID-19 symptoms. Age and work experience were divided into two groups based on the median values, and frequency and percentage values were used for analysis. The difference in the number of COVID-19 symptoms according to the general and COVID-19-related characteristics was analyzed using independent-sample t-tests. Pearson's Chi-squared test and independent-sample t-tests were also used to analyze the differences between COVID-19-related characteristics across obesity groups. A p-value of < .005 was considered statistically significant.

General characteristics of the study participants

Table 1 shows the general characteristics of the study participants. Out of the 180 participants, 124 (68.9%) were women with a mean age of 42.83 ± 7.22 years. Only 19 (10.6%) of the participants currently smoked, and half of them drank alcohol more than twice a month over the past year. Approximately 52.2% (94) exercised regularly, and 44 (24.4%) were overweight or obese. The majority of the participants had no underlying diseases (89.4%). Of all the participants, 17.2% (31) and 149 were flight attendants and cabin attendants, respectively. Additionally, the mean work experience was 214.12 ± 99.40 months, which is approximately 17.84 years.

Table 1

General characteristics of the study participants
Variables	Total
Variables	n (%) or Mean ± SD	Range
Age (years)	42.83 ± 7.22	26–59
≤44	91 (50.6)
>44	89 (49.4)
Sex
Male	56 (31.1)
Female	124 (68.9)
Smoking
Yes	19 (10.6)
No	161 (89.4)
Consumption of alcohol in the past year
More than twice a month	90 (50.0)
Less than once a month	90 (50.0)
Regular exercise
Yes	94 (52.2)
No	86 (47.8)
BMI (kg/m²)
Normal (< 23.0)	136 (75.6)
Overweight/obese (≥ 23.0)	44 (24.4)
Baseline comorbidities
Yes	19 (10.6)
No	161 (89.4)
Job
Cockpit crew	31 (17.2)
Cabin crew	149 (82.8)
Work experience (months)	214.12 ± 99.40	37–420
≤241	90 (50.0)
>241	90 (50.0)
Number of COVID-19 symptoms	3.14 ± 1.98	0–9
Duration of COVID-19 symptoms
< 4 weeks	136 (74.4)
> 4 weeks	46 (25.6)
Time to return to flight duties
After < 1 week	103 (57.2)
After > 1 week	77 (42.8)
Impact on daily activities due to post-COVID-19 symptoms
Yes	65 (36.1)
No	115 (63.9)
SD, standard deviation; BMI, body mass index; COVID-19, coronavirus disease 2019

Characteristics associated with COVID-19 among study participants

Out of the 180 participants, 158 (87.7%) reported having COVID-19-related symptoms, and the mean number of COVID-19-related symptoms among the participants was 3.14 ± 1.98 (range 0–9). Among the 158 participants, 74.4% (136) had COVID-19-related symptoms for < 4 weeks. Among all participants, 42.8% (77) returned to their flight duties more than a week after completing treatment. Approximately 36.1% experienced ongoing impacts on their daily life due to COVID-19-related symptoms even after treatment was completed (Table 1).

Symptoms of COVID-19 at onset of illness

Table 2 shows the symptoms of COVID-19 at the onset of illness. Out of the 180 participants, 22 had no symptoms at onset. Among the 158 participants who did have symptoms, the most common ones were fatigue (79.7%), cough (63.9%), and myalgia (63.3%). Only five participants had a sore throat (3.2%).

Table 2

Symptoms of COVID-19 at the onset of illness
Symptoms	n (%)
Respiratory symptoms
Breathlessness	21 (13.3)
Cough	101 (63.9)
Rhinorrhea, sputum	6 (3.8)
Cardiovascular symptoms
Chest pain or discomfort	23 (14.6)
Palpitation	2 (1.3)
Gastrointestinal symptoms
Diarrhea/heartburn	2 (1.3)
Weight loss	2 (1.3)
Psychological symptoms
Anxiety/depression/helplessness	13 (8.2)
Musculoskeletal symptoms
Myalgia (muscle or joint pain)	100 (63.3)
Neurological symptoms
Headache	5 (3.2)
Dizziness	1 (0.6)
Sleep disturbances	21 (13.3)
Generalized symptoms
Fever	11 (7.0)
Fatigue	126 (79.7)
Ear, nose, and throat symptoms
Smell or taste disorder	85 (53.8)
Sore throat	5 (3.2)
COVID-19, coronavirus disease-2019

Differences in the number of COVID-19 symptoms according to general characteristics

Table 3 presents the differences in the number of COVID-19 symptoms according to the general characteristics of the study participants. There were significant differences in sex (t=-2.39, p = .018), smoking (t=-2.71, p = .007), drinking in the last year (t=-2.52, p = .013), and BMI (F = 5.18, p = .007). The number of COVID-19 symptoms was higher in women than in men. Additionally, participants who currently did not smoke and drank less than once a month had more COVID-19 symptoms. Overweight or obese participants had more COVID-19 symptoms compared to those with normal or low weight.

Table 3

Differences in the number of COVID-19 symptoms according to general characteristics
Variables	Number of COVID-19 symptoms
Variables	Mean ± SD	t(p)
Age (years)		-0.69(.494)
≤44	3.04 ± 1.78
>44	3.25 ± 2.18
Sex		-2.39(.018)
Male	2.63 ± 1.95
Female	3.38 ± 1.96
Smoking		2.71(.007)
Yes	2.00 ± 1.89
No	3.28 ± 1.96
Consumption of alcohol in the past year		2.52(.013)
More than twice a month	2.78 ± 1.92
Less than once a month	3.51 ± 1.95
Regular exercise		0.94(.349)
Yes	3.01 ± 1.84
No	3.29 ± 2.14
BMI (kg/m²)		2.89(.004)
Normal (< 23.0)	3.38 ± 1.98
Overweight/obese (≥ 23.0)	2.41 ± 1.82
Baseline comorbidities		-0.03(.975)
Yes	3.16 ± 2.34
No	3.14 ± 1.95
Job		1.85(.066)
Cockpit crew	2.55 ± 2.22
Cabin crew	3.27 ± 1.92
Working experience (months)		-1.51(.133)
≤241	2.92 ± 1.82
>241	3.37 ± 2.12
COVID-19, coronavirus disease 2019; BMI, body mass index; SD, standard deviation

Differences in the number of COVID-19 symptoms by characteristics associated with COVID-19

Table 4 shows the differences in the number of COVID-19 symptoms according to the characteristics related to COVID-19. Significant differences were observed in participants with COVID-19-related symptoms lasting > 4 weeks (t=-6.19, p < .001), and participants experiencing difficulties in daily activities due to post-COVID-19 symptoms (t=-4.40, p < .001). In other words, greater number of COVID-19 symptoms indicated the longer duration of the symptoms, and participants continued to experience discomfort in daily activities even after completing treatment. However, this was not significantly associated with returning to flight duties.

Table 4

Differences in the number of COVID-19 symptoms according to characteristics related to COVID-19
Variables	Number of COVID-19 symptoms
Variables	Mean ± SD	t(p)
Duration of COVID-19 symptoms		-6.19(< .001)
< 4 weeks	2.66 ± 1.70
> 4 weeks	4.57 ± 2.08
Time to return to flight duties		0.92(.359)
After < 1 week	3.26 ± 2.03
After > 1 week	2.99 ± 1.92
Impact on daily activities due to post-COVID-19 symptoms		-4.40(< .001)
Yes	4.29 ± 2.24
No	2.73 ± 1.71
COVID-19, coronavirus disease 2019; SD, standard deviation

A difference in the number of COVID-19 symptoms and the time to return to flight duties was observed according to weight (Table 5). The number of COVID-19 symptoms was significantly higher in participants with normal weight compared to those who were overweight or obese (t = 2.87, p = .004). The time to return to flight duties after completing COVID-19 treatment was significantly longer in participants with normal weight compared to those who were overweight or obese (t = 4.17, p = .041).

Table 5

Differences in COVID-19-related characteristics across obesity groups
Variables	Normal	Overweight /Obese	t/χ²(p)
Variables	n (%) or Mean ± SD	n (%) or Mean ± SD	t/χ²(p)
Number of COVID-19 symptoms	3.38 ± 1.98	2.41 ± 1.82	2.87(.004)
Duration of COVID-19 symptoms			2.85(.091)
< 4 weeks	97 (71.3)	37 (84.1)
> 4 weeks	39 (28.7)	7 (15.9)
Time to return to flight duties			4.17(.041)
After < 1 week	71 (52.9)	31 (70.5)
After > 1 week	64 (47.1)	13 (29.5)
Impact on daily activities due to post-COVID-19 symptoms			3.45(.063)
Yes	41 (30.1)	7 (15.9)
No	95 (69.9)	37 (84.1)
COVID-19, coronavirus disease 2019; SD, standard deviation

We aimed to determine the impact of COVID-19 symptoms on airline crew. It is significant as the first study conducted to assess the effects of COVID-19 symptoms among airline crew in Korea.

Fatigue was found to be the most common symptom of COVID-19 in this study, which aligns with previous research.¹⁹ However, the previously reported symptoms of high fever and dyspnea were less prevalent.^{1, 20} There are several plausible explanations for this. Firstly, it may be because the study participants were airline crew who experienced fatigue due to jet lag or shift work, unrelated to COVID-19 infection. Secondly, there may be differences in the characteristics of the study participants. Only a small percentage (approximately 11%) of the subjects in this study had underlying diseases, whereas past studies included approximately 51% with underlying health conditions ²⁰. High fever and dyspnea are risk factors that contribute to the severity of COVID-19, and healthy adults may exhibit fewer symptoms of high fever and dyspnea. Lastly, the timing of data collection may have influenced the results. The previous study collected data in 2020 during the early stage of the pandemic, whereas this study collected data in September 2022, when the pandemic had progressed. The coronavirus has also continued to spread worldwide since 2020, with ongoing mutations until the end of the pandemic, resulting in different symptom presentations among infected individuals. In 2022, variants such as Omicron BA4 and BA5 were prevalent, leading to common reports of fatigue even among individuals who had sufficient sleep at night.²¹

Nonsmokers or ex-smokers experienced more symptoms when diagnosed with COVID-19 compared to smokers. This unexpected finding suggests that smoking may have a protective effect. Similarly, individuals who drank less than once a month had a higher number of symptoms than those who drank more than twice a month. This could be because individuals who pay more attention to their symptoms are more likely to report them. Since symptoms are subjective and vary depending on how an individual perceives their health, considering factors such as sex and mood when interpreting symptom reports is important. In the previous study, it was discovered that nonsmokers and low drinkers were more likely to report physical symptoms, which can be influenced by sex and negative moods.² In the present study, additional analysis revealed that approximately 80% of nonsmokers in the study were women, and approximately 83% of individuals who drank less than once a month were also women. Another possible explanation for these findings is that the symptoms experienced by the study participants were relatively mild. For instance, the rates of dyspnea and chest pain, which are considered serious symptoms of COVID-19, were low at 13.3% and 14.6%, respectively. Notably, previous studies that reported higher rates of complications and mortality in smokers or ex-smokers typically involved individuals with more severe symptoms.^{9, 22} However, making direct comparisons in this study was challenging because the smoking habits of the study participants were not directly measured; only 13 individuals in the study smoked daily. It has been reported that smoking and ex-smoking are associated with the severity of COVID-19, which aligns with previous research indicating higher rates of complications and mortality.^{9, 10, 22}

The findings of this study demonstrated that the number of symptoms was higher in cases where COVID-19 symptoms persisted for a longer duration. This result is consistent with previous studies.^{23, 24} These studies found that when the number of symptoms reaches five or more, it increases the likelihood of developing long COVID syndrome, which lasts for > 4 weeks. In our study, individuals who experienced symptoms for > 4 weeks had an average of five symptoms during the acute phase. A larger number of symptoms can significantly impact daily life, potentially indicating a more severe illness and longer recovery period. Notably, previous research has shown that post-COVID syndrome lasting > 12 weeks after diagnosis negatively affects quality of life. Therefore, it is highly plausible that the duration of symptoms affects daily life. However, the number of symptoms in the individuals examined in this study did not influence their timing of returning to work. This is likely because most airlines allow employees to return to work after completing the 7-d national quarantine period, as long as their symptoms are not severe. Hence, it is crucial for internal health managers to continue monitoring symptoms even after employees have returned to work, especially in cases where individuals have experienced multiple COVID-19 symptoms.

The results of this study revealed that the number of symptoms was lower in obese or overweight patients compared to normal-weight patients, and these individuals also returned to work faster. This is in contrast to previous studies which reported that obesity affects COVID-19 severity through impaired respiratory function.²⁵ There are several possible reasons for this discrepancy. First, the obese or overweight group may have had a higher proportion of men. It is known that women tend to complain of symptoms more frequently than men, and they also have a higher incidence of long COVID-19 syndrome, where symptoms persist for > 4 weeks ²⁶. In fact, the results of this study showed that approximately 93% of the obese group consisted of men, which was higher compared to the 11% in the normal weight group. Second, the overweight or obese group included a larger proportion of flight attendants, approximately 50%, in contrast to the 7% in the normal weight group. Since flight attendants do not have direct contact with passengers, they could return to work as long as they were deemed capable of performing their duties, despite having persistent symptoms. On the other hand, cabin attendants, who interact with passengers directly, would not have been able to resume work until all major symptoms had disappeared. Lastly, the average BMI of subjects classified as obese in this study was 24.4, which is lower compared to previous studies where a BMI of 30 or higher was used to define obesity ²⁷.

This study has certain limitations. First, it should be noted that the results are not easily applicable to the wider population, as the study was only conducted on Korean airline crews. Further studies are necessary to confirm the relationship between weight and COVID-19 symptoms specifically in airline crews. Second, there is a possibility of recall bias, as participants had to recall their symptoms at the time of COVID-19 infection when answering the questionnaire. Additionally, the proportion of obese or overweight participants was relatively low, accounting for only approximately 24% of the total participants.

This study found that fatigue symptoms were the most commonly reported by airline crew members infected with COVID-19. Given that the management of fatigue among airline crew is crucial not only for their personal health but also for flight safety, airlines should make efforts to address the fatigue of infected crew members. Interestingly, smokers, those who consumed alcohol more than twice a month, and those who were obese reported fewer COVID-19 symptoms. This suggests that airline crew members who took better care of their health may have been more attentive to symptom management after being infected with COVID-19, resulting in more reported symptoms. However, since smoking and obesity are considered risk factors for COVID-19 severity, airlines should also prioritize the health management of members with mild symptoms.

Conflict of interest

The authors declare that they have no conflict of interest.

Funding

This work was supported by the Dong-A University research fund.

Author Contribution

Conceptualization, K.J.H.; methodology, K.J.H. and J.Y.W.; investigation, K.J.H.; data curation, software, and formal analysis; J.Y.W., writing – original draft preparation; K.J.H. and J.Y.W.; writing – review and editing, K.J.H. and J.Y.W. All authors have read and agreed to the published version of the manuscript.

Barek M.A., M.A. Aziz,M.S. Islam. Impact of age, sex, comorbidities and clinical symptoms on the severity of COVID-19 cases: A meta-analysis with 55 studies and 10014 cases. Heliyon, 2020; 6(12).
Kolk A.M., G.J. Hanewald, S. Schagen, et al. A symptom perception approach to common physical symptoms. Soc Sci Med 2003; 57(12): 2343-2354.
Görlich Y.,D. Stadelmann, Mental health of flying cabin crews: Depression, anxiety, and stress before and during the COVID-19 pandemic. Front Psychol, 2020; 11: 581496.
Jeong YW., Kim JH. Depression, Anxiety, Stress and Anger of the Cabin Crew during the COVID-19 Pandemic in South Korea. Healthcare 2022; 10(10): 1952.
Kim JH., Choi S. Effects of Post-COVID-19 Syndrome on Quality of Life Among Airline Crew. Workplace Health Saf, 2024; 21650799241253870.
Jain V.,J.-M. Yuan, Predictive symptoms and comorbidities for severe COVID-19 and intensive care unit admission: a systematic review and meta-analysis. Intl J Public Health, 2020; 65: 533-546.
Hu J.,Y. Wang, The clinical characteristics and risk factors of severe COVID-19. 2021, S. Karger AG Basel, Switzerland. p. 255-266.
Ko A.C.S., A. Candellier, M. Mercier, et al., Number of initial symptoms is more related to long COVID-19 than acute severity of infection: a prospective cohort of hospitalized patients. Int J Infect Dis, 2022; 118: 220-223.
Gülsen A., B.A. Yigitbas, B. Uslu, et al., The effect of smoking on COVID-19 symptom severity: systematic review and meta-analysis. Pulm Med, 2020.
Hopkinson N.S., N. Rossi, J. El-Sayed_Moustafa, et al., Current smoking and COVID-19 risk: results from a population symptom app in over 2.4 million people. Thorax, 2021; 76(7): 714-722.
Merino J., A.D. Joshi, L.H. Nguyen, et al., Diet quality and risk and severity of COVID-19: a prospective cohort study. Gut, 2021; 70(11): 2096-2104.
Malisoux L., A. Backes, A. Fischer, et al., Associations between physical activity prior to infection and COVID-19 disease severity and symptoms: results from the prospective Predi-COVID cohort study. BMJ open 2022; 12(4): e057863.
Cheng W.A., L. Turner, C.J. Marentes Ruiz, et al., Clinical manifestations of COVID‐19 differ by age and obesity status. Influenza Other Respir Viruses 2022; 16(2): 255-264.
Ye P., R. Pang, L. Li, et al., Both underweight and obesity are associated with an increased risk of coronavirus disease 2019 (COVID-19) severity. Front Nutr 2021; 8: 649422.
Anker M.S., U. Landmesser, S. von Haehling, et al., Weight loss, malnutrition, and cachexia in COVID‐19: facts and numbers. 2021, Wiley Online Library. 9-13.
World Health Organization. The Asia-Pacific perspective: redefining obesity and its treatment. 2000.
Shah W., T. Hillman, E.D. Playford, et al., Managing the long term effects of covid-19: summary of NICE, SIGN, and RCGP rapid guideline. BMJ 2021; 372.
Weng L.-M., X. Su,X.-Q. Wang, Pain symptoms in patients with coronavirus disease (COVID-19): a literature review. J Pain Res 2021; 147-159.
Seeßle J., T. Waterboer, T. Hippchen, et al., Persistent symptoms in adult patients 1 year after coronavirus disease 2019 (COVID-19): a prospective cohort study. Clin Infect Dis 2022; 74(7): 1191-1198.
Chen N., M. Zhou, X. Dong, et al., Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. The lancet 2020; 395(10223): 507-513.
Looi M.-K., How are covid-19 symptoms changing? BMJ 2023; 380.
Vardavas C.I.,K. Nikitara, COVID-19 and smoking: A systematic review of the evidence. Tob Induc Dis 2020; 18.
Aiyegbusi O.L., S.E. Hughes, G. Turner, et al., Symptoms, complications and management of long COVID: a review. J R Soc Med 2021; 114(9): 428-442.
Di Matteo R., T. Bolgeo, D. Gatti, et al., Post-Covid-19 Syndrome: symptoms and stratified follow-up. A systematic review and meta-analysis. Working Paper of Public Health 2022; 10(1).
Yu W., K.E. Rohli, S. Yang, et al., Impact of obesity on COVID-19 patients. J Diabetes Complications 2021; 35(3): 107817.
Bai F., D. Tomasoni, C. Falcinella, et al., Female gender is associated with long COVID syndrome: a prospective cohort study. Clin Microbiol Infect 2022; 28(4): 611. e9-611. e16.
Huang J.-F., X.-B. Wang, K.I. Zheng, et al., Obesity hypoventilation syndrome and severe COVID-19. Metabolisml 2020; 108.

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You are reading this latest preprint version

COVID-19 symptoms and obesity in Korean airline crew

Status:

Version 1

Abstract

Introduction

Methods

Study design

Participants

1) General questionnaire

Data collection procedures

Ethical considerations

Data analysis

Results

General characteristics of the study participants

Characteristics associated with COVID-19 among study participants

Symptoms of COVID-19 at onset of illness

Differences in the number of COVID-19 symptoms according to general characteristics

Differences in the number of COVID-19 symptoms by characteristics associated with COVID-19

Discussion

Conclusion

Declarations

Conflict of interest

Funding

Author Contribution

References

Additional Declarations

Status:

Version 1